Journal
SCIENCE OF THE TOTAL ENVIRONMENT
Volume 539, Issue -, Pages 494-502Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.scitotenv.2015.07.138
Keywords
Bacterial indicators; Culture-based methods qPCR; Environmental waters; Solid particles; Sunlight inactivation
Categories
Funding
- NIH - Fogarty International Center from University of California at Davis [D43 TW005718]
- National Institute of Environmental Health Sciences
- Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)
Ask authors/readers for more resources
In this work, sunlight inactivation of two indicator bacteria in freshwater, with and without solid particles, was studied and the persistence of culturable cells and total DNA was compared. Environmental water was used to prepare two matrices, with and without solid particles, which were spiked with Escherichia coli and Enterococcus faecalis. These matrices were used to prepare microcosm bags that were placed in two containers: one exposed to sunlight and the other in the dark. During one month, samples were removed from each container and detection was done by membrane filter technique and real-time PCR. Kinetic parameters were calculated to assess sunlight effect. Indicator bacteria without solid particles exposed to sunlight suffered an immediate decay (<4 h) compared with the ones which were shielded from them. In addition, the survival of both bacteria with solid particles varied depending on the situation analyzed (T-99 from 3 up to 60 days), being always culturable E. coli more persistent than E. faecalis. On the other side, E. faecalis DNA persisted much longer than culturable cells (T-99 > 40 h in the dark with particles). In this case active cells were more prone to sunlight than total DNA and the protective effect of solid particles was also observed. Results highlight that the effects caused by the parameters which describe the behavior of culturable microorganisms and total DNA in water are different and must be included in simulation models but without forgetting that these parameters will also depend on bacterial properties, sensitizers, composition, type, and uses of the aquatic environment under assessment. (C) 2015 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available